<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>04_作用域_面试题</title>
</head>
<body>
<script type="text/javascript">
  /*
   问题: 结果输出多少?
   */
  var x = 10;
  function fn() {
    console.log(x);
  }
  function show(f) {
    var x = 20;
    fn()
  }
  show(fn);
</script>
</body>
</html>